This invention relates to organosilicon fine particles having a new shape and a method of producing such organosilicon fine particles, as well as polymer modifiers and cosmetic materials comprising such organosilicon fine particles.
Organosilicon fine particles comprising polysiloxane network structures are widely being used as polymer modifiers, cosmetic materials, coating materials, diagnostic agent carriers and paint materials. This invention relates to such organosilicon fine particles having a circular ring shape as a whole.
Examples of such organosilicon fine particles which have conventionally been known include (1) those that are solid and spherical with smooth surface (such as disclosed in U.S. Pat. Nos. 4,652,618 and 4,892,726 and Japanese Patent Publications Tokkai 61-159467, 61-194009, 63-15849, 63-8461, 63-77940, 63-312324, 1-144423, 2-209927, 4-337390, 6-279589 and 6-49209); (2) those that have many indentations on the surface and are solid and spherical as a whole (such as disclosed in Japanese Patent Publication Tokkai 2000-191788); (3) those that are sectionally horseshoe-shaped (such as disclosed in Japanese Patent Publication Tokkai 2000-191789); (4) those that are hollow and semi-spherically shaped (such as disclosed in Japanese Patent Publication Tokkai 2003-128788); and (5) those in the shape of a rugby ball (such as disclosed in Japanese Patent Publication Tokkai 2003-171465). These prior art organosilicon fine particles are noted as polymer modifiers and cosmetic materials because of their lubricity, non-stickiness, oil-absorbing property, dispersibility, heat-resistance, resistance against solvents and water repellency.
These prior art organosilicon fine particles have problems, however, when used as a polymer modifier or a cosmetic material because they are not sufficiently effective for the purpose. When such prior art organosilicon fine particles are used as an antireflection agent for an antireflection film of a liquid crystal display, for example, there is the problem that the product turns out to be inferior in antireflection property and clarity of transmitted image. If they are used as an antiblocking agent for a polymer film, as another example, there is the problem that the product turns out to be inferior in adherence resistance and anti-slip. If they are used as a cosmetic material for a skin care, furthermore, there is the problem that they are inferior in stickiness and slip.